import java.util.Scanner;

public class Main {

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int cases = sc.nextInt();
    while (cases-- > 0) {
        double y = sc.nextInt();
        double x = sc.nextInt();
        calculatBinaryTree(x, y);
    }
}

public static void calculatBinaryTree(double x, double y) {
    int z = (int) (x / y * 100);
    int t = 0;
    int start = 0;
    int end = 2000000000;
    int i = ((start + end) / 2);    
    while (true) {
        // System.out.println("i = " + i);
        // System.out.println("start = " + start);
        // System.out.println("end = " + end);
        t = (int) ((x + i) / (y + i) * 100);
        // System.out.println("(x + i) / (y + i) * 100) = " + t);
        if (t >= z + 1) {
            end = i;
        } else {
            start = i;
        }

        i =  ((start + end) / 2);
        if (i == start || i == end)
            break;
        if (i <= 0) 
        {
            System.out.println(-1);
            return;
        }
    }
    if ((int) ((x + start) / (y + start) * 100) >= z + 1)
        System.out.println(start);
    else if ((int) ((x + end) / (y + end) * 100) >= z + 1)
        System.out.println(end);        
    else
        System.out.println(-1);
    return;
}

}